1. Field of the Invention
The present invention relates to a stereo image display device that is capable of making a stereo image recognized based on a right-eye image and a left-eye image, and specially relates to a technique that enables binocular vision through a semi-transparent mirror.
2. Description of the Related Art
Conventionally, a device of the above type may be a stereo image display device, which includes, for example, a first display portion configured to display a first image serving as a left-eye image, a second display portion configured to display a second image serving as a right-eye image, a semi-transparent mirror provided at a corner portion formed between the first display portion and the second display portion, a chromaticity adjusting portion configured to adjust a chromaticity of the first display portion and the second display portion, and a luminance adjusting portion configured to adjust a luminance of the first display portion and the second display portion (for example, see Patent Document 1). The above stereo image display device suppresses the variation of chromaticity and luminance of both of the display portions through the chromaticity adjusting portion and the luminance adjusting portion.
In the above conventional device, although nothing is described about the calibration, an optical sensor is used for the calibration in general. Although different from the above stereo image device, the followings are examples, in which the optical sensor is used for a display device capable of displaying a two dimensional image.
There is a first image display device that includes a calibration optical sensor provided separate from the image display device, and the optical sensor is brought into a tight contact with a liquid crystal display panel to execute the calibration (for example, see Patent Document 2). The device is capable of accurately executing the calibration without the influence of disturbance, such as ambient light.
Also, there is a second image display device, in which a calibration optical sensor is provided to a bezel part of the liquid crystal display panel (for example, see Patent Document 3). The above device is configured such that, the optical sensor is received within the bezel part when the liquid crystal display panel is caused to display the image, and also that the optical sensor is advanced toward the liquid crystal display panel only when the calibration is executed. As a result, when the image is displayed, the optical sensor will not hinder the display, In addition to it, when the calibration is executed, the optical sensor is advanced so that the calibration is quickly executed. Also, the device is capable of accurately executing the calibration without the influence of disturbance, such as ambient light.
In order to execute the calibration for the above conventional stereo image display device, for example, it is assumed that a calibration optical sensor is provided at a viewpoint located between the semi-transparent mirror of the stereo image display device and the observer. It is also assumed that, for example, the calibration optical sensor described in the above Patent Document 2 is provided to each of the display portions.    Patent Document 1: JP-A-2004-241962 (FIG. 1, FIG. 2)    Patent Document 2: JP3751621 (FIG. 1)    Patent Document 3: JP-A-2007-193355 (FIG. 1)